Clay was selected by the St. Louis Rams in the sixth round (201st overall) of the 1996 NFL draft.[4] As a rookie, he was the third-string tight end, appearing in 11 games, and started 4 contests after Troy Drayton was injured and Aaron Laing had to replace the starting fullback. He caught four passes for 51 yards. He registered 4 receptions for 51 yards.
He was waived on August 30, 1997. In 1998, he was signed by the Rams and was released before the start of the season.
On June 24, 1998, he signed a two-year contract with the Chicago Bears.[5] He was released on August 30.[6]
August 31, 1998, he was claimed off waivers by the Dallas Cowboys.[7] Although he began the season as the third-string tight end, a knee injury to starter David LaFleur allowed him to play in the last three games of the season, starting two. On December 20 against the Philadelphia Eagles, he caught his only pass of the year, for 27 yards.
On August 31, 1999, he was placed on injured reserve list with a knee injury he suffered in training camp, as a result he missed the entire season.[8] He was cut on February 10, 2000.
On May 16, 2000, he was signed as a free agent by the Miami Dolphins.[9] On July 27, he had arthroscopy surgery on his left knee,[10] which would limit him during training camp. He was cut on August 22.[11]
In 2001, Clay was selected in the eleventh round (84th overall) of the XFL draft by the Orlando Rage.